title: Bone mineral changes after lactation in Gambian women accustomed to a low calcium intake.
abstract: OBJECTIVE
  Previous studies in Gambian women with a low calcium intake have described decreases in whole-body and regional bone mineral content (BMC) and areal bone mineral density (aBMD) during the first year of lactation. The aim of this study was to examine whether these effects are reversed after lactation.
  
  
  METHODS
  Thirty-three Gambian women who had a previous dual-energy X-ray absorptiometry (DXA) scan at 52 weeks lactation (L52) were invited to participate in a follow-up study when neither pregnant nor lactating (NPNL) for ≥3 months and/or when 52 weeks postpartum in a subsequent lactation (F52). Whole body, lumbar spine and hip bone mineral were measured by DXA. Anthropometry and dietary assessments were also conducted. Repeated-measures analysis of covariance was used to determine differences from L52 at NPNL and F52.
  
  
  RESULTS
  Twenty-eight women were scanned at NPNL and 20 at F52. The mean±s.d. calcium intake of the 33 women at NPNL and F52 was 360±168 mg/day. BMC, aBMD and size-adjusted BMC (SA-BMC) at all sites were higher at NPNL than L52. Percent increases in SA-BMC (mean±s.e.m.) were significant (P<0.0001): whole body=2.7±0.4%; lumbar spine=4.9±1.0%; total hip=3.7±1.0%. There were no significant differences in any measurements between the two lactation time points (L52 and F52).
  
  
  CONCLUSIONS
  This study of Gambian women with low calcium intakes demonstrates that bone mineral mobilised during lactation is recovered after lactation. Successive periods of long lactation are not associated with progressive skeletal depletion.
authors.affiliation: MRC Keneba, West Kiang, The Gambia.
authors.forename: Y
authors.initials: Y
authors.lastname: Sawo
authors.forename: L M A
authors.initials: LM
authors.lastname: Jarjou
authors.forename: G R
authors.initials: GR
authors.lastname: Goldberg
authors.forename: M A
authors.initials: MA
authors.lastname: Laskey
authors.forename: A
authors.initials: A
authors.lastname: Prentice
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000704:Analysis of Variance; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D001942:Breast Feeding; D002118:Calcium / Q000008:administration & dosage / Q000378:metabolism*; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000378:metabolism*; D004032:Diet; D005260:Female; D005500:Follow-Up Studies; D005714:Gambia; D006615:Hip; D006801:Humans; D007774:Lactation / Q000378:metabolism*; D008159:Lumbar Vertebrae; D055815:Young Adult
chemical_list: D002136:Calcium, Dietary; D002118:Calcium